The Colon Cancer Family Registry - Australasia (CCFR-A) has made an important and substantial contribution to the Colorectal Cancer Family Registry (Colon CFR), an international resource for collaborative, interdisciplinary studies of the etiology, prevention, and clinical management of colorectal cancer (CRC). The CCFR-A has recruited almost 30% of participants and provided more than 60% of known mutation carriers. We recruited and obtained epidemiology information for 28,366 participants from 1,707 families, and collected 7,411 blood samples and 1,869 tumor specimens from 1,408 CRCs. We have demonstrated that Australia and New Zealand are excellent countries from which to recruit both population-based and clinic-based families. Standout qualities of the CCFR-A include the large number of participants per family (e.g. >8 bloods per clinic-based family), and high response rates in terms of biospecimens (blood, tissue), clinical data collection and follow-up. We have consistently performed close to or above expectation,, despite adverse currency fluctuations over Phase II. The CCFR-A performs high quality molecular and genetic characterization, and in Phase III will conduct all of the Colon CFR mutation testing for BRAF and PMS2 and perform the IHC work for Seattle and DSC consortium registries. We have been selected to be a major recruiter of families. The CCFR-A is an essential component of the Colon CFR. In accordance with the U24 mechanism and "Strategic Plan", our specific aims for Phase III are: 1. Expand 200 families already participating in the Colon CFR that are known, or expected to be identified during Phase III, to carry deleterious mutations in the mismatch repair (MMR) genes or the MYH gene. 2. Recruit 160 additional families, through Australian cancer family clinics, who are known to carry an MMR gene or MYH mutation or meet Amsterdam I and II criteria (including Type X families). 3. Conduct passive and active follow-up for 2,860 population-based and 3,263 clinic-based subjects. 4. Obtain clinical information for 333 Phase I probands on stage, treatment and outcomes. 5. Collaborate with and support the Molecular Characterization Core by dispatching biospecimens data, and conducting IHC work for two other CFR registries and testing for BRAF and PMS2 for entire Colon CFR. Maintain the biospecimens core, process and add to the core all new samples from subjects recruited in Phase III, and coordinate future efforts with the planned Central Repository. 7. Maintain the local bioinformatics core and coordinate efforts with the ISC. 8. Maintain the administrative core. We have shown we can accomplish these aims. In doing so will enhance the infrastructure of the Colon CFR, an outstanding resource for studies of the causes and prevention of CRC.